Skip to content

drivers: spi: Add support for LSB transfer for rpi_pico_pio #34

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: v3.5.0+zmk-fixes
Choose a base branch
from
Open

drivers: spi: Add support for LSB transfer for rpi_pico_pio #34

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 10 additions & 6 deletions drivers/spi/spi_rpi_pico_pio.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -103,6 +103,7 @@ static int spi_pico_pio_configure(const struct spi_pico_pio_config *dev_cfg,
const struct gpio_dt_spec *mosi;
const struct gpio_dt_spec *clk;
pio_sm_config sm_config;
bool lsb = false;
uint32_t offset;
uint32_t wrap_target;
uint32_t wrap;
Expand All @@ -122,10 +123,13 @@ static int spi_pico_pio_configure(const struct spi_pico_pio_config *dev_cfg,
return -ENOTSUP;
}

if (spi_cfg->operation & SPI_TRANSFER_LSB) {
LOG_ERR("Unsupported configuration");
return -ENOTSUP;
}
/* Note that SPI_TRANSFER_LSB controls the direction of shift, not the */
/* "endianness" of the data. In MSB mode, the high-order bit of the */
/* most significant byte is sent first; in LSB mode, the low-order */
/* bit of the least-significant byte is sent first. */
if (spi_cfg->operation & SPI_TRANSFER_LSB) {
lsb = true;
}

#if defined(CONFIG_SPI_EXTENDED_MODES)
if (spi_cfg->operation & (SPI_LINES_DUAL | SPI_LINES_QUAD | SPI_LINES_OCTAL)) {
Expand Down Expand Up @@ -199,9 +203,9 @@ static int spi_pico_pio_configure(const struct spi_pico_pio_config *dev_cfg,

sm_config_set_clkdiv(&sm_config, clock_div);
sm_config_set_in_pins(&sm_config, miso->pin);
sm_config_set_in_shift(&sm_config, false, true, bits);
sm_config_set_in_shift(&sm_config, lsb, true, bits);
sm_config_set_out_pins(&sm_config, mosi->pin, 1);
sm_config_set_out_shift(&sm_config, false, true, bits);
sm_config_set_out_shift(&sm_config, lsb, true, bits);
sm_config_set_sideset_pins(&sm_config, clk->pin);
sm_config_set_sideset(&sm_config, 1, false, false);
sm_config_set_wrap(&sm_config, offset + wrap_target, offset + wrap);
Expand Down
Loading